Wireless telecommunications networks often use procedures for controlling the transmit power of forward link signals (i.e., signals transmitted from a base station to a mobile station) and/or the transmit power of reverse link signals (i.e., signals transmitted from a mobile station to a base station). For example, code division multiple access (CDMA) networks may use an “inner loop” process and an “outer loop” process for controlling the transmit power of forward link and/or reverse link signals.
In a conventional “inner loop” process, a receiving device receives a wireless signal transmitted by a transmitting device. The receiving device periodically assesses the strength of the received signal, such as by determining the signal-to-noise ratio (SNR), and compares the observed value to a setpoint. If the observed value is lower than the setpoint, the receiving device instructs the transmitting device to increase the transmit power of the wireless signal. If the observed value is higher than the setpoint, the receiving device instructs the transmitting device to lower the transmit power of the wireless signal.
In a conventional “outer loop” process, the receiving device periodically determines a frame error rate (FER) in the received signal and compares the observed FER to a target FER. Conventionally, the target FER is set by the wireless service provider and remains fixed during the power control process. The receiving device may adjust the setpoint used for power control based on the comparison between the observed FER and the target FER. If the observed FER is higher than the target FER, the receiving device may increase the setpoint, which may lead to a corresponding increase in the transmit power level via the “inner loop” process. If the observed FER is lower than the target FER, the receiving device may decrease the setpoint, which may lead to a corresponding decrease in the transmit power level via the “inner loop” process.